$\dfrac{3}{4} - \dfrac{1}{3} = {?}$
Solution: $ = {\dfrac{3 \times 3}{4 \times 3}} - {\dfrac{1 \times 4}{3 \times 4}} $ $ = {\dfrac{9}{12}} - {\dfrac{4}{12}} $ $ = \dfrac{{9} - {4}}{12} $ $ = \dfrac{5}{12}$